// @(#)VariableSizeQueueImpl.java   9/2002
// Copyright (c) 1998-2002, Distributed Real-time Computing Lab (DRCL) 
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
// 
// 1. Redistributions of source code must retain the above copyright notice,
//    this list of conditions and the following disclaimer. 
// 2. Redistributions in binary form must reproduce the above copyright notice,
//    this list of conditions and the following disclaimer in the documentation
//    and/or other materials provided with the distribution. 
// 3. Neither the name of "DRCL" nor the names of its contributors may be used
//    to endorse or promote products derived from this software without specific
//    prior written permission. 
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// 

package drcl.util.queue;

/** Base class for implementing a queue with variable-size elements. */
public abstract class VariableSizeQueueImpl extends QueueImpl
    implements VariableSizeQueue
{
  public void enqueue(double key_, Object element_)
  { enqueue(key_, element_, 1); }
  
  public boolean enqueueAt(int pos_, double key_, Object element_)
  { return enqueueAt(pos_, key_, element_, 1); }
  
  public boolean enqueueAfter(Object previousElement_, Object element_)
  { return enqueueAfter(previousElement_, element_, 1); }
  
  public abstract void enqueue(double key_, Object element_, int size_);
  
  public boolean enqueueAt(int pos_, double key_, Object element_,
          int size_)
  {
    throw new QueueOptionalImplException(getClass() + 
          "doesn't implement enqueueAt(int, double, Object, int)");
  }
  
  public boolean enqueueAfter(Object previousElement_, 
          Object element_, int size_)
  {
    throw new QueueOptionalImplException(getClass() + 
            "doesn't implement enqueueAfter(Object, Object, int)");
  }
  
  public void merge(Queue that_)
  {
    double[] keys_ = (double[]) that_.keys();
    Element[] elements_ = that_._retrieveAll();
    for (int i=0; i<elements_.length; i++) {
      Element e_ = elements_[i];
      if (e_.getSize() == 1)
        enqueue(keys_[i], e_.getObject());
      else
        enqueue(keys_[i], e_.getObject(), e_.getSize()); 
    }
  }
    
  public void enqueue(Object element_, int size_)
  { enqueue(isEmpty()? 0.0: lastKey(), element_, size_); }
  

  public abstract int getSize();

  public String info(String prefix_, boolean listElement_)
  {
    StringBuffer sb_ = new StringBuffer(super.toString() + "," + getSize() 
            + "/" + getLength() + "\n");
    if (listElement_ && !isEmpty()) {
      double[] keys_ = keys();
      Object[] elements_ = retrieveAll();
      for (int i=0; i<keys_.length; i++)
        sb_.append(prefix_ + keys_[i] + "\t" + elements_[i] + "\n");
    }
    return sb_.toString();
  }

  public void duplicate(Object source_)
  {
    VariableSizeQueueImpl q_ = (VariableSizeQueueImpl)source_;
    reset();
    if (!q_.isEmpty()) {
      double[] keys_ = q_.keys();
      Element[] elements_ = q_._retrieveAll();
      for (int i=0; i<keys_.length; i++) {
        Element e_ = elements_[i];
        if (e_.getSize() == 1) enqueue(keys_[i], e_);
        else enqueue(keys_[i], e_, e_.getSize());
      }
    }
  }
}
